I can’t really tell anything regarding the wear or life of those heads from the pics. The dummy head could have been rotated, or the heads relapped. I don’t see anything that spells certain disaster, but there’s no way to know how far off that is without a proper head report. One of the pictures shows some unevenness to the wear pattern.
How much price-wise is reasonable? There really isn’t a market for this stuff, so it really comes down to how much you are willing to pay. They are rare, and the market for the 388 has gone silly high. So it seems people can ask a lot for a complete headblock assembly and not be insane. If I needed one in this day and age, like if I depended on my 388 and I knew verifiably my current headstack was dying, I can see myself paying $400 for one *with a head report*.